Gall watching is the new bird watching
Looking for a new hobby? When plants are infested by certain organisms, they produce abnormal plant tissue growths known as galls. But how do you know what is causing these growths – is it a wasp? A virus? Or something else? With a jar and a notebook, you can become a gall detective in your own backyard! Read on to learn more.
In a new article out recently in American Entomologist, USGS scientists and collaborators describe how you can get into the exciting hobby of “gall watching.”
It all starts with an observation: maybe you see a weird, miscolored wart on stems of the oak tree in your backyard, or a fuzzy lump on the leaves of a maple tree on the sidewalk. You can draw, photograph, paint, or simply take notice of the gall.
Photos: oak trees parasitized by a variety of gall wasps.
The next step is identifying the type of gall, maybe from a website like gallformers.com or through an app like iNaturalist. This might narrow your gall observation down to a few species of gall-forming wasps that lay their eggs in oak tree leaves.
How do you find out which species is it is? Knowing something about the biology of a gall can help. For example, galls formed by wasps typically contain wasp eggs or larva. You can determine what type of wasp laid those eggs by taking a leaf or stem containing galls, adding it to a jar or plastic tub, and bringing it home to see exactly what hatches. And don’t worry – these aren’t wasps that will sting or hurt you.
Photos: Red cone galls on an oak tree, and a wasp emerging from a red cone gall in someone's home. All photos from iNaturalist.
Ready to take on this new endeavor or want to learn more?